Crystal structure and Hirshfeld surface analysis of (5aS,8aR)-3,5a-dimethyl-8-methylidene-2-oxododecahydrooxireno[2′,3′:6,7]naphtho[1,2-b]furan-6-yl (Z)-2-methylbut-2-enoate extracted from Ferula persica

In the crystal of the title compound, adjacent molecules are connected by intermolecular C—H⋯O hydrogen bonds, forming a three-dimensional network.


Chemical context
Sesquiterpene lactones are a significant group of natural products isolated from the extracts of various parts of medicinal plants. As a medicinal plant, the Ferula genus is rich in coumarins, specifically sesquiterpene coumarins. Ferula species are found in the Mediterranean region, Central Asia, Siberia, China, Afghanistan, Iran, North Africa and the Caucasus (Mir-Babayev & Houghton, 2002). The members of this genus typically have a heavy fragrance due to the presence of essential oils or oleoresins in their content. This genus is applied for the cure of various organ disorders in folk medicine (Salehi et al., 2019). These herbs have been used for oleogum resin, plant extracts, and essential oils. Moreover, the essential oils and extracts of different species of this herb can be used as natural food preservatives due to their antioxidant and antimicrobial activity (Daneshniya et al., 2021).

Supramolecular features and Hirshfeld surface analysis
In the crystal of the title compound, adjacent molecules are connected by intermolecular C-HÁ Á ÁO hydrogen bonds, forming a three dimensional network (Tables 1 and 2). Figs. 2, 3 and 4 show packing views of the title compound down the a, b and c axes, respectively.
CrystalExplorer17 (Spackman et al., 2021) was used to compute Hirshfeld surfaces of the title molecule. The d norm mappings for the molecule were performed in the range À0.1633 to +1.3364 a.u. The locations of the C-HÁ Á ÁO interactions are shown by intense red circles on the d norm surface (Fig. 5a,b).

Table 2
Summary of short interatomic contacts (Å ) in the title compound.

Figure 2
View of the packing of the title compound down the a axis.
The largest difference between the two structures (I and II) lies in the cyclohexane B ring, which is of the rigid-chair type in I and of the flexible boat type in II. In both crystal structures, the molecules are held together mostly by van der Waals forces.

Synthesis and crystallization
The title compound has previously been isolated from the roots of the Ferula oopoda plant and fully characterized (Serkerov, 1972). The compound used for the current study was isolated from the roots of the Ferula persica herb by a similar method.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.